The diferrence between the normal and the heroic difficulty, is a new ability that involves raid damage, plus an add the each individual that gets it has to handle it personally. But let's start over with the standard abilities.

Triple Puncture: A brutal tri-horned strike that inflicts 600.000 Physical damage and increases the damage taken from Triple Puncture by 10% for 1.50min. This effect stacks.

Double Swipe: Horridon swings his massive head and tail to and fro, inflicting 462500 to 537500 Physical damage to players in a 35-yard cone in front of and behind himself. This effect happens twice.

Charge: Horridon charges at a random player, performing a Double Swipe once he reaches their location.

Dire Call: Horridon emits a powerful roar, inflicting 270000 Physical damage and increasing the melee attack speed of all allies by 50%. The power of the Dire Call also summons forth a Direhorn Spirit.

Risen Drakkari Champion: Once called to action, Risen Drakkari Champions pour from the Drakkari tribal door until it is destroyed.

Uncontrolled Abomination: The foul necromantic magics that animated the last remnants of the Drakkari tribe left them bereft of intelligence and purpose, causing the Risen Drakkari to attack random targets.

Drakkari Frozen Warlord: A total of three Drakkari Frozen Warlords will jump down from the arena stands once the Drakkari are called to action.

Mortal Strike: A powerful blow inflicts 350% weapon damage and leaves the player wounded, reducing the effectiveness of any healing received by 50% for 8 sec.

Frozen Orb: Summons an orb of frozen power that shoots a bolt of frost at a nearby enemy target every 1 sec, inflicting 46250 to 53750 Frost damage and slowing movement speed by 20% for 2 sec.

The Amani

War-God Jalak will call upon the Amani tribe to enter the arena last.

Amani'shi Protector: Once called to action, Amani'shi Protectors pour from the Amani tribal door until it is destroyed.

Amani'shi Flame Caster: Once called to action, Amani'shi Flame Casters pour from the Amani tribal door until it is destroyed.

Fireball: Hurls a ball of fire at a random player, inflicting 138750 to 161250 Fire damage.

Amani Warbear: A total of three Amani Warbears will jump down from the arena stands once the Amani are called to action.

Swipe: The warbear swipes with its claws, inflicting 166500 to 193500 Physical damage to players in a 0-yard cone.

Amani'shi Beast Shaman: Amani'shi Beast Shaman ride atop the powerful Amani Warbears and can be attacked once the Warbear has fallen.

Chain Lightning: The Beast Shaman calls upon the spirits of the storms to inflict 120250 to 139750 Nature damage to a player. Chain Lightning can jump to another player within 5 yards, affecting 3 total targets and increasing damage by 50% per jump.

Hex of Confusion: Hexes a player for 30 sec, giving them a 50% chance to injure themselves for 55500 to 64500 Physical damage when casting a spell or using an ability.

War-God Jalak and his faithful Zandalari Dinomancers will come to the aid of Horridon during the battle.

Zandalari Dinomancer: Zandalari Dinomancers will jump down into the arena periodically.

Dino-Mending: The dinomancer channels a beam of healing energy at Horridon, healing 1% of Horridon's maximum health every 1 sec.

Dino Form: At 50% health, the dinomancer transforms into a powerful Devilsaur, increasing Physical damage dealt by 50% but preventing the dinomancer from casting Dino-Mending.

Orb of Control: When the Zandalari Dinomancer transforms, it drops its Orb of Control. A player can interact with the orb to temporarily dominate Horridon's mind, forcing the beast to charge into a tribal door. Destroying a tribal door prevents additional members of that tribe from entering the arena.

Headache: Charging into a tribal door gives Horridon a terrible headache, stunning him for 10 sec.

Cracked Shell: Horridon's shell cracks after ramming into a door, increasing damage taken by 50%. This effect stacks up to 4 times.

War-God Jalak: After all four tribes have been called, or when Horridon has been damaged below 30% health, War-God Jalak himself will enter the arena.

Rampage: War-God Jalak's death causes Horridon to go on a rampage, increasing damage dealt by 100% and attack speed by 50%.

Phase 1:

The encounter involves the boss summoning adds in each gate, that will have to be dealt with in order to procceed to phase 2.

Each gate has a set of important adds that have to be prioritized. The boss will also spawn Dinomancers that will help you move the boss to the next gate.

In the first gate the boss will spawn Stonegazers,Farraki Skirmishers,Farraki Wastewalkers.

The important adds in this gate are the Wastewalkers. They will cast some magic abilities at the raid that have to be dispelled, or else they will deal some damage. When the Dinomancer comes, you will have to bring him to 50% so that he spawns an orb, which you will have to click for the boss to charge on the gate, destroy it and move to the next one.

In the second gate the boss will spawn Gurubashi Bloodlords, Gurubashi Venom Priests.

The important adds in this gate are the Venom Priests. They will cast some poison abilities to the raid that have to be dispelled, plus they will also spawn some poison zones on the ground that have to be avoided. Same goes as above, when the Dinomancer spawns he has to be DPS'd until 50% for the orb to spawn and the boss to move on to the next gate.

In the third gate the boss will spawn Risen Drakkari Warriors,Champions and Frozen Warlords.

The important adds in this gate are the Risen Frozen Warlords. They will spawn Frozen Orbs on the ground that have to be avoided at all costs because they will deal a good amount of damage to whoever stands near them. When the Dinomancer comes, focus him and procceed to the final gate.

In the final gate the boss will spawn Amani'shi Protectors, Flame Casters, Amani Warbears and amani'shi Beast Shamans.

The important adds in this gate are the Beast shamans. They will cast curses on the raid, that have to be dispelled, along with Lightning Nova totems on the ground that have to be avoided as well. The raid will have to be somewhat spread at this point, because the Beast Shamans also cast chain lightning.

After Horridon reaches 30%, phase 2 will come.

Phase 2:

When Horridon reaches 30% he will summon the other mini/secondary boss called War-God Jalak.

He will often cast an AoE ability dealing damage to the raid, that will stack the more casts are happening. Therefore, you have to kill him before moving on killing Horridon.

After he dies, he will buff Horridon with a 50% increase on damage done, and attack speed.

After that, it's only Horridon left and when you kill him you will be done with the encounter.

What differs from normal mode:

At certain points, Horridon will cast an AoE ability called Dire Call. The raid will take some damage and adds will spawn.(called Direhorn Spirits)

A random player will be fixated by this add, and when it reaches him, the player will die. This add is only visible by the player that is fixated and it can be knocked away when you deal damage to it. DoT effects don't work, only direct damage.

Tanks: 2

The standard main tank and off-tank combination to deal with the taunt rotation.

Healers: 6

A safe mix of healers that can dispel poison/magic/curse effects is ideal for this encounter. Having strong AoE raid healing is a plus.

DPS: 17:

A combination of multi-dotting classes is very strong in this fight. Warlocks,Shadow Priests,Moonkins will deal the most damage, due to the big amount of adds during the encounter.

Shadow Priest (Artzie)

Choose Twist of Fate for this fight, it's uptime will be very high due to the amount of adds dieing throughout the whole encounter. You can also choose between Halo and Cascade, personally i prefer Halo.If you get focused by a Direhorn Spirit, cast a SW: Pain on it occassionally for it to be knocked away.Place your dots accordingly, and follow the priority on the adds for each gate.

Resto Shaman (Sonie)

Decurse, decurse, decurse!!!!

When you get your pink dinosaur put Searing Totem and Flame Shock ur dino and the totem will deal with it.

Make sure everyone stands in your Healing Rain in the last phase so they get the bonus hp to survive the AoE.

Warlock (Sparkuggz)

Destruciton and Affliction is viable on this boss. You wan't to try to keep dots running on Horridon at all times if you want to keep your DPS up, but during progress be sure to focus your main DPS into the adds at all times. Destruction with Mannoroth's Fury and Fire and Brimstone can help destroy the adds fast, and as Affliction you can multi dot endlessly. Use a pet (Fel Imp) to keep your Dire Beast off you, be sure to call your pet back now and then so it wont despawn.